Wound healing is an integral part of every surgical procedure, and in 1992 there were 34 million injury related visits to emergency rooms at a cost of 9.2 billion dollars in the United States alone. Stress has been shown to prolong the time course of healing and increase the risk of infection. The long-term objectives of this proposal are to elucidate the mechanisms by which stress impairs wound healing and to determine how this impairment can be ameliorated. This will be done using a well-characterized murine model of stress impaired healing that parallels stress effects seen in humans. The specific aims are as follows: I. Determine the effects of hyperoxia on stress-impaired healing. II. Assess the role of alpha-adrenergic receptors in stress-impaired wound oxygen levels and healing. The outcomes by which these aims will be assessed include delay in closure, level of oxygenation, quantity of bacteria and neutrophils, oxygen-dependent gene expression and nitric oxide synthesis. The results of the proposed experiments will potentially be used to develop therapeutic interventions that will benefit a broad population.